//题目：宏#define命令练习(2)
//1.程序分析：
//2.程序源代码：
#include "stdio.h"
#define exchange(a,b) { \
	int t;\
	t = a;\
	a = b;\
	b = t;\
	}

int main(void) {
	int x = 10;
	int y = 20;
	printf("x=%d; y=%d\n", x, y);
	exchange(x, y);
	printf("x=%d; y=%d\n", x, y);
	return 0;
}
